Railway-traffic-controlling apparatus



Patented Jan. 3,1928.

UNITED STATES PATENT OFFICE.

ROBERT M. GILSON, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, 01' SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

- RAILWAY-TRAEFIC-CONTROLLING APPARATUS.

Application medley 29, 1928. Serial No. 112,500.

My invention relates to railway traflic controlling apparatus, and particularly to apparatus of the type comprising train carried governing means controlled by energy received from the trackway.

I will describe one form of railway traflic controlling apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawing is a diagram matic view illustrating one form of railway 'traific controlling apparatus embodying my invention.

Referring to the drawing, the reference characters 1 and 1 designate the track ralls ofi a stretch of railway track over which trafiic-normally moves in the direction ndicated by the arrow. These rails are divided, by means of insulated joints 2, to form a plurality of track sections, only one of whlch,

A-B, is illustrated in the drawing. As here shown each track section is provided with a trackway signal which is controlled in accordance with traific conditions by .means forming no part of my present inventlon and omitted from the drawing for the sake of simplicity. These signals may be of any suitable form and are here shown as semaphore signals each designated by the ref. erence character S with an exponent cor-. responding to the location. and each capable of displaying a proceed, a caution or a stop indication. Associated with signal S are two circuit controllers O and D. Circuit.

controller C comprises a movable lever 7. and circuit controller D comprises a movable lever 10. Levers 7 and 10 are controlled by signal-S toswing into engagement with selected ones of fixed contacts. assoc ated therewith in accordance with the position of the signal, as will be clear from the drawing.

Train controlling current is at times supplied to the rails. of section AB by a track 15 and 16, contact 78 of circuit controller so that the circuit just traced for the relay,

becomes interrupted. After a time interval due to the slow releasing characteristics of the relay, the back contact 14 again closes and current is again supplied to the relay. It follows as long as signal S indicates caution or proceed, relay R is operated intermittently. Due to the slow releasing characteristics of the relay, its front contact 21-21 is closed for a longer interval of time than its back contact 2121 during each complete cycle of operation of the relay. When signal S indicates stop, circuit controller G is open and relay R is continuously de-energized.

The supply of train controlling current to the rails of section AB by secondary 3 of transformer T is controlled by circuit controller D and by relay R. The left-hand terminal of secondary 3. of transformer T is constantly connected, through wire 22, with nected with rail 1 of the section through wire 25, contact 10--11 of circuit controller D, wire 26, front contact 21-21of-relay' R, Y

and wires 27 and 28. This circuit is closed only when signal .S indicates proceed and front contact 21-21 of relay R is closed.

When signal S indicates caution the righthand terminal of secondary 3 of transformer T is connected through wire 25, contact 1012 of circuit controller D, wire29, back contact 2121' of relay R, and wiresf27 and 28 to rail 1 of section A-B. This circuit is closed only when signal S indicates caution and relay R is open. When signal S indicates caution or proceed, however, relay R is operated intermittently as has been explained hereinbefore. It follows, therefore, that when either of the two circuits just traced'is closed, current'is supplied to the rails of section A-'-B in the form of code impulse combinations made up of impulsesof energy separated by time intervals. The

relative lengths of the time intervals that alternating current is. supplied to the track rails for the code impulse combination corresponding to the proceed and caution indications of signal S may be regulated by properly designing the relay R. For example, I will assume that a complete cycle of operation of relay R occupies one second, and that front contact 2121 is closed for two-thirds of a second and back contact 2121" is closed for one-third of a second. during each such complete cycle, When Sig-o nal S indicates proceed, therefore, code impulse combinations are supplied to the trackway according to the proceed code which comprises impulses -of energy each lasting for two-thirds of a second and separated by time intervals of one-third of a second. 'VVhen signal S indicates caution however, codeimpulse combinations are supsection A-B without interruption.

It is understood that each track section is provided with apparatus similar to that just described for section AB.

The reference character V indicates train which is provided with receiving apparatus designated in general by the reference character W. This receiving apparatus comprises two magnetizable cores 23 and 23 carried the train in inductive relation with the two track rails 1 and 1 respectively, and located in advance of the forward axle of the train. Core 23 is provided with a winding 24, and core 23 is provided with a similar winding 24, the two windings 24 and 24 being connected in series in such manner that the voltages induced therein by alternating currents flowing in opposite directions in-the two track rails at an-instant are additive. The windings 24 and 24' are connected, through an amplifier 31 with a relay K.

Relay K is therefore energized durin each impulse of alternating current supplied to the rails by transformer T. Associated with this relay is a transformer Q comprising a core 33 provided with a primary 34 and a secondary 35. A slow. releasing relay designated by the reference character J is connected with secondary 35 of transformer Q through an asymmetrical unit 36. Primary 34 oftransformer Q is provided with one circuit which may be traced from a suitable source of direct current such as a battery F,

through wire 37, front contact 32 of relay K, wire 38, primary 34 of transformer Qf, wire 30, back contact 40-40 of relay J, and wires 41 and 42 back to battery F. This circuit is closed only when relay J is deenergized and when relay Kis energized. Thecurrent then builds up to a steady value in primary 3 1- and creates a magnetic flux in core 33. The asymmetrical unit 36 is so arranged that when the circuit just traced is closed the growth of the mag netic field created by the current in primary 34 creates a voltage in secondary tion in which the asymmetrical unit 36 conducts more readily. Due to the slow releasing characteristics of relay J, this relay maintains its front contacts closed during the interval which elapses between successive surges of energy supplied to the relay J during the caution .or proceed codes. When relay J is-energized a second circuit is completed for primary 34 of transformer Q, which may be traced from battery F, througl'r wire 37, front contact 32 of relay K, wire 38; primary 34 of transformer Q, wire 39, front contact 404O of relay J, wire 43, winding of relay H, and wires 44, 45 46, 47, and 42, back to'battery F. \Vhentiis circuit is closed, the electromotive force of battery F is connected across the terminals of primary 34 and relay H in series. Due to the reactive impedance of primary 34 the current resulting from this electromot-ive force increases slowly to its maximum value. It follows that a time interval elapses after the closing of the circuit including relay I-I before the current .through the relay incrpases to the value necessary to pick up the re ay.

In explaining the operation of the apparatus as a whole, I will first assume that signal S indicates proceed so that the rails of section AB are being supplied with code impulse combinations in accordance with the proceed code. Assuming that relay J is deenergized, the first time contact 32 of relay i K closes a surge of direct current flows supplied to relay J during the decay of this fie causing relay J a to become energized.

Front contact 40 is therefore closed so that when relay K next becomesenergized the closing of front contact 32 supplies a a second, as is the case when the proceed code is being supplied to the trackway, a suflicient time elapses for relay H to become energized. Due to the slow acting characteristics of relays J and H, these relays keep their front contacts closed as long as relay K is intermittently operated in accordance with the proceed code. With both these relays energized currentflows from battery F, through wire 48, front contact 5050- of relay J, wire 49, front contact 51-51 of relay H, wire 52, lamp 55 and wires 45, 46, 47, and 42, back to battery F. Lamp 55 is therefore lighted to indicate rocee'd.

I will now assume t at signal S indicates caution so that section A B is supplied with code impulse combinations in accordance with the caution code. The'first impulse of this code closes contact 32 of relay K and builds up the current in primary 34 of transformer Q, and the subsequent opening of front contact 32 during the time interval between successive impulses in the trackway allows the decaying field of transformer Q to create a voltage in secondary 35 which energizes relay J. Front contact 40'40 of relay J .is therefore closed so that the next "succeeding impulse in the trackway', by closing contact 32 of relay K, connects relay H in series with primary 34 across battery F. The proportioning of the parts is such that when front contact 32 is closed for only one-third of ,a second as is the case when .the trackway is being supplied with the caution c0de,the reactive impedance of primary 34 retardsthe growth of current in relay H to such an extent that.

the current in the relay does not increase to a value sufiicient to energize the relay be fore the relay circuit 1s again opened. When the train is being supplied with code impulse combinations in accordance with the caution code, relay J is continuously energized, but the comparatively short impulses which are supplied to relay H under these conditions are not sufficient to energize this relay so that its back contact 5151 remains closed. Under these conditions, current flows from battery F, through wire 48, front contact 50-50 of relay J, wire-49, back contact 5151 of relay H, wire 53, lamp 56 and wires 46,47 and 42, back to battery F. Lamp 56 is therefore lighted to indicate caution;

When signal S indicatesstop, uninterrupted alternating current s supplied to the rails of section A-B-so that relay K is I 5O50 ofrelay J, wire 54, lamp 57 and wires 47 and 42, back to battery F. Lamp 57- is therefore lighted to indicatestop.

It should also be pointed out that should the supply of alternating current to the rails of the section for any reason be interrupted, relay K would be continuously de-energized. Relay J would then be continuously decnergized and lamp 57 would be lighted to indicate stop. Y

It will therefore be seen that relay J is a checking relay which is energized when interrupted current is supplied to the trackway according to either'code, but that relay 1-.[ is a selecting relay which is responsive to the length of each impulse supplied to the trackway and is energized only if these impulses are of the length corresponding to the proceed v.code. 7 Although I have herein shown and described only one form of railway traflic controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of they appended claims without departing from the spirit/and scope of my invention.

Having thus described my invention, what I claim is: 1. In combination, a source of direct current, a relay, and means for at times periodically connecting said relay with said source for different intervals of time, such means including a reactive impedance connected in series with said relay to retard the growth of current in the relay so that the relay is responsive to the lengths of the intervals during which it is connected with the source. 2. In combination, a train carried relay, means for periodically energizing said relay for different intervals of time, a source of direct current, a second relay, a circuit for said second relay including a contact of said train carried relay and said source, an inductive reactance included in said circuit for retarding the growth of current in said second relay, and governing means selectively controlled by said second relay in accordance with the lengths of the intervals during which such relay is connected with the source 4 2 3. In combination, a transformer having a primary and a secondary," means for supplying the primary with a series of direct current impulses, a relay, and means for supplying current to said relay from the secondary of said transformer during the decay of the magnetic field created by each such impulse in the rimary of the transformer but not during t 1e growth of such magnetic field.

4. In combination, a. train carried trans-' former having a primary and a secondary, means located partly in the trackway for at times supplying the primary of said transformer with impulses of direct current, a relay, means for supplying current to said relay from the secondary of said transformer during the decay of the magnetic field created by each such impulse in the primary of the transformer but not during the growth of such magnetic field, and governing meanscontrolled by said relay.

-5. In combination, a transformer having a primary and a secondary, means for supplying the primary with a series of direct current impulses, a relay connected with the secondary of said transformer and an asymmetrical un1t connected in series with said relay to permit current to flow'through the relay during the decay of the magnetic field created by each impulse in the primary of said transformer but to prevent the 'flow of current in said relay during the growth of such field.

6. Railway traflic controlling apparatus comprising a stretch of railway track supplied at times with periodic impulses of current, a first relay responsive to such impulses, a transformer having a" rimary and a secondary, means controlled by. said first relay for periodically supplying the primary of said transformer with direct current imulses an as mmetrical unit a second rela Q a y a connected with the secondary of said transformer through said asymmetrical unit, a third relay, means controlled by said second relay for at times connecting said third relay in series with said primary, and govern- 1119; means controlled by said third relay.

7. Railway traflie controlling apparatus comprising a stretch of railway track supplied at times with periodic impulses of current, a first relay responsive to such impulses, atransformer. having a primary and a secondary, means controlled by said first relay for periodically supplying the primary of said transformer with directcurrent impulses, an asymmetrical unit, a second relay connected with the secondary of said transformer through said asymmetrical unit,'a-

third relay, means controlled by said second relay for at times connecting said third relay in series with said rimary, and governing means controlled by said second relay and by said third relay.

8. Railway tratfic controlling apparatus comprising a stretch of railway track-sup-' impulse in said primary, a third relay. means controlled by said second relay for at times connecting sald third relay in series with the primary of said transformer and governing means controlled by said second and third relays,

9. Railway traflic controlling apparatus comprising a first train carried relay, means located partly in the trackway for periodically energizing said relay, a source of direct current, a transformer having a primary and a secondary, a second relay connected with the secondary of said transformer, a third relay; a circuit for the primary of said transformer including said source, a front contact of said first relay, and a back cont-act of said second rela a-second circuit for such primary inclu in said source, a front contact of said first re ay, a front contact of said second relay, and the winding of said third relay; and governing means controlled by said second and third relays.

10. Railway traific cont-rolling apparatus current, a second relay arranged to be energized when said first relay is receiving impulses of either length, a third relay controlled by said first and second relays and energized only when said first relay is receiving said long impulses, and governing means controlled by sald' second and third relays.

11. Railway traflic controlling apparatus comprising a train carried relay, means located partly in the trackway for at times periodically supplying. the relay with comparatively short impulses, and for at other times periodically supplying the relay with comparatively long impulses, a slowreleasing relay, a source of current, means for connecting said slow releasing relay with said source during each such impulse, a reactive impedance in series with said slow releasing for at times supplying said first relay with impulses of one length and for at other times supplying the relay with impulses of a different length, a transformer having a primary and a secondary, means for supplying direct current to the primar when said first relay is energized, a secon relay receiving energy from the secondary of said transformer during the decay of the magnetic field created by each impulse in the primary of the transformer, a third relay connected in series with the primarv of said transformer when said second relayis energized such third relay being energized when the first relay is receiving impulses of one length but not when the first relay is receiving impulses of the other length, and governing means controlled by said second relay.

13. Railway trafiic controlling apparatus way for difierent proportions of a given interval of time, a first train carried relay selectively responsive to the pro ortion of arated by time intervals, a first train car-.

ried relay energized during such impulses but not during suchtime intervals, a second train carried relay controlled by the first relay and responsive to alternate energization and de-energization thereof, a third train carried relay controlled by the first relay and selectively responsive to the relative average lengths of such impulses and time intervals, and governing means controlled jointly by said second and third relays.

In testimony whereof'I aflix my signature.

ROBERT GILSON. 

